Engine crankshaft indexing method and tool

Abstract

A crankshaft rotation tool and method is provided to facilitate test and repair adjustments requiring precise indexing of rotational degrees of the crankshaft. The tool engages and imparts rotation to existing bolts mounting an existing pulley to the crankshaft.

We claim: 
     
       1. In an internal combustion enging having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft by a nut, and a disc mounted to said pulley by a plurality of bolts and covering said nut, a method for rotating siad crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, comprising removing one or more of said bolts, removing said disc, providing a tool having a disc and an axial shank, engaging said tool disc with the remaining of said bolts, and rotating said shank to rotate said tool disc to impart rotation to said pulley and said crankshaft. 
     
     
       2. The invention according to claim 1 comprising disengaging said tool disc from said remaining bolts after said rotational indexing, and replacing said first mentioned disc against and reinserting said removed bolts. 
     
     
       3. The invention according to claim 2 comprising, after engaging said tool disc with said remaining bolts reinserting at least one of said removed bolts back through said tool disc and into said pulley to retain said tool disc on said pulley during said rotational indexing to facilitate same, particularly in high compression applications, such as in diesel engines, and then removing said last mentioned bolt after said rotational indexing, then disengaging said tool disc from said remaining bolts, then reinstalling said first disc against and reinserting said removed bolts through said first disc and into said pulley. 
     
     
       4. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a disc mounted to said pulley, a method for rotating said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, comprising providing a central keyed opening in said disc axially colinear with said crankshaft, inserting a keyed shank axially into said disc in keyed relation with said opening, rotating said shank to rotate said disc, said pulley and said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, and removing said shank from said central keyed opening in said disc following said indexing rotation, said disc remaining in place on said engine after said rotational indexing. 
     
     
       5. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a disc mounted to said pulley, a method for rotating said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, comprising providing a shank on said disc extending axially therefrom on the opposite side thereof from said crankshaft and axially colinear with said crankshaft, and rotating said shank to rotate said disc, said pulley and said crankshaft to provide said rotational indexing, leaving said disc and said shank in place on said engine after said rotational indexing, without removing said disc and said shank. 
     
     
       6. In an internal combustion engine having a crankshaft extending axially from a crankcase, a first pulley mounted to said crankshaft, a disc mounted to said first pulley, and a second pulley mounted to said disc, a method for rotating said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft without requiring removal of either of said pulleys nor said disc, comprising providing a central keyed opening in said disc coaxial with said crankshaft, inserting a shank having an outer keyed configuration through said second pulley and into said keyed opening in said disc in keyed relation therewith, rotating said shank to rotate said disc, said second pulley, said first pulley, and said crankshaft to provide said rotational indexing, removing said shank from said keyed opening in said disc axially through said second pulley. 
     
     
       7. In an internal combustion engine having a crankshaft extending axially from a crankcase, a first pulley mounted to said crankshaft, a disc mounted to said first pulley, and a second pulley mounted to said disc, a method for rotating said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, without removing either of said pulleys nor said disc, comprising providing a shank extending axially through said second pulley from the side of said disc opposite said crankshaft and axially colinear with said crankshaft, rotating said shank to rotate said disc, said second pulley, said first pulley and said crankshaft to provide said rotational indexing, said shank remaining on said disc and extending axially through said second pulley after said rotational indexing. 
     
     
       8. In an internal combustion engine having a crankshaft extending axially from a crankcase, a first pulley mounted to said crankshaft, a disc mounted to said pulley by a first plurality of bolts, a second pulley mounted to said disc by a second plurality of bolts, a method for rotating said crankshaft to facilitate test and repair adjustments requiring precise indexing of rotational degrees of said crankshaft, comprising removing said second plurality of bolts, removing said second pulley from said disc, removing one or more of said first plurality of bolts, removing said disc, providing a tool having a tool disc and an axial shank extending therefrom, engaging said tool disc with the remaining of said first plurality of bolts, rotating said shank to rotate said tool disc, said first pulley and said crankshaft to provide said rotational indexing, removing said tool, reinstalling said first mentioned disc and reinserting the remaining of said first plurality of bolts, and reinstalling said second pulley and reinserting said second plurality of bolts. 
     
     
       9. The invention according to claim 8 comprising reinserting at least one of the removed of said first plurality of bolts through said tool disc into said first pulley prior to said rotational indexing, and then removing said last mentioned at least one bolt after said rotational indexing. 
     
     
       10. A crankshaft rotation tool for an internal combustion engine having a crankshaft extending axially from a crankcase, and a pulley mounted to said crankshaft, said tool comprising a disc removably attachable to said pulley and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating said shank, disc, pulley and crankshaft, to facilitate test and repair adjustments requiring precise indexing of rotation degrees of said crankshaft, a second pulley mounted to said disc on the opposite side from said crankshaft and having an axial opening therethrough, and wherein said disc remains attached to said first mentioned pulley after said test and repair adjustments. 
     
     
       11. The invention according to claim 10 wherein said shank is integrally attached to said disc and remains in said axial opening in said second pulley after said test and repair adjustments. 
     
     
       12. The invention according to claim 10 wherein said disc has a central keyed opening therein receiving said shank in keyed relation said shank being removed from said keyed opening in said disc through said axial opening in said second pulley after said test and repair adjustments. 
     
     
       13. A crankshaft rotation tool for an internal combustion engine having a crankshaft extending axially from a crankcase, and a pulley mounted to said crankshaft, said tool comprising a disc removably attachable to said pulley and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating said shank, disc, pulley and crankshaft, to facilitate test and repair adjustments requiring precise indexing of rotation degrees of said crankshaft, wherein said tool is a two-piece member comprising said disc and said shank, said disc having a central keyed opening therein removably receiving said shank therein in keyed relation. 
     
     
       14. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a plurality of bolts around a periphery of said pulley radially outward of the axis of rotation of said crankshaft, a crankshaft rotation tool comprising a disc removably attachable to said pulley at said bolts, said disc extending radially from said axis of rotation and having a plurality of openings around its periphery and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating same about said axis of rotation, said disc at said peripheral openings engaging respective of said bolts to impart rotation to said pulley and said crankshaft upon rotation by said shank, wherein said bolts have enlarged heads at their ends, and wherein at least one of said openings around said periphery of said disc has a diameter larger than the diameter of its respective said bolt head and slides thereover upon attachment of said disc to said pulley without removal of said bolt from said pulley, and wherein at least another of said openings around said periphery of said disc has a diameter less than the diameter of its respective said bolt head such that the last mentioned respective bolt must be removed from said pulley and then reinserted through said last mentioned opening and into said pulley to retain said disc on said pulley and provide secure retention of said disc on said pulley in high torque applications, including high compression ratio engines such as diesel engines, and prevent slippage of said disc off said pulley during indexing rotation. 
     
     
       15. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a plurality of bolts around a periphery of said pulley radially outward of the axis of rotation of said crankshaft, a crankshaft rotation tool comprising a disc removably attachable to said pulley at said bolts, said disc extending radially from said axis of rotation and having a plurality of openings around its periphery and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating same about said axis of rotation, said disc at said peripheral openings engaging respective of said bolts to impart rotation to said pulley and said crankshaft upon rotation by said shank, wherein said bolts have enlarged heads at their ends, and wherein all of said openings around said periphery of said disc have a diameter larger than the diameter of their respective bolt heads and slide axially thereover upon attachment of said disc to said pulley, and slide axially thereoff upon removal of said disc from said pulley, all without requiring removal and reinstallation of any of said bolts. 
     
     
       16. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a plurality of bolts around a periphery of said pulley radially outward of the axis of rotation of said crankshaft, a crankshaft rotation tool comprising a disc removably attachable to said pulley at said bolts, said disc extending radially from said axis of rotation and having a plurality of openings around its periphery and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating same about said axis of rotation, said disc at said peripheral openings engaging respective of said bolts to impart rotation to said pulley and said crankshaft upon rotation by said shank, wherein said engine includes a harmonic balancer mounted by said bolts to said pulley between said pulley and said disc, said disc engaging said bolts and imparting said rotation without removal of said harmonic balancer. 
     
     
       17. In an internal combustion engine having a crankshaft extending axially from a crankcase, a pulley mounted to said crankshaft, and a plurality of bolts around a periphery of said pulley radially outward of the axis of rotation of said crankshaft, a crankshaft rotation tool comprising a disc removably attachable to said pulley at said bolts, said disc extending radially from said axis of rotation and having a plurality of openings around its periphery and having a shank extending axially from said disc on the opposite side of said disc from said crankshaft and axially colinear with said crankshaft, said shank being grippable for rotating same about said axis of rotation, said disc at said peripheral openings engaging respective of said bolts to impart rotation to said pulley and said crankshaft upon rotation by said shank, wherein said engine includes a second pulley mounted to said disc on said opposite side thereof from said crankshaft, wherein said disc is attached to said pulley by said bolts and remains attached after said test and repair adjustments, and wherein said second pulley has an axial opening therethrough receiving said shank, and wherein said second pulley remains attached to said disc during said test and repaired adjustments during indexing rotation by said shank without requiring removal of said second pulley from said disc. 
     
     
       18. The invention according to claim 17 wherein said shank is integrally connected to said disc and extends axially through said axial opening in said second pulley and remains therein after said test and repair adjustments. 
     
     
       19. The invention according to claim 17 wherein said disc has a central configured opening therein receiving said shank in keyed relation, and wherein said shank is removed from said central opening in said disc through said axial opening in said second pulley after said test and repair adjustments.